Paraffin scraping device



Jan. 23, 1951 E. H. CHRISTOPHER PARAFFIN SCRAPING DEVICE Filed April 1, 1949 I n vento r E manual H. Chrisiapher Patented Jan. 23, 1951 UNITED STATES mew-r orrice 7 2,538,762 PABAFFIN SCRAPING DEVICE Emanuel H. Christopher, Bowie, Tex.

Application April l, 1949, Serial No. 85,014

4 Claims.

This invention relates to a well scraping device and is particularly designed for use in removing paraffin and other substances from the wall of the bore in well tubing.

A principal object of this invention is to remove the paraffin from the well tubing only on the upstroke, so that the parafiin is prevented from falling down into the well.

Another important object of this invention is to enable a plurality of vertically spaced scrapers to be lowered into a well tubing without contacting the side walls thereof and to automatically bring the scrapers into engagement of the side walls on the upstroke, so that the cutters or scrapers define a circular cutting knife, whereby the entire inner surface of the tubing is scraped.

Another important object of this invention is to provide an elongated supporting rod on which are disposed a plurality of slide members disposed in end-toend relationship out of longitudinal alignment, each of the slide members being formed with an inwardly and upwardly inclined side wall, with respect to the longitudinal axis of the supporting rod, and to provide a plurality of scrapers which are slidably disposed on the slide members and which are formed with a side wall complementary to the inclined side wall of the slide members. Thus, when the supporting rod is lowered into the well tubing, the scrapers are frictionally held at the upper end of the slide members and the cutting portions pf the scrapers which project laterally from the portion of the scraper complementary to the inclined side walls of the slide members are retained out of engagement with the side walls of the well tubing. However, upon the upstroke of the supporting rod, the cutting surfaces of the scrapers are brought into engagement of the well tubing. The side walls of the slide members which are inclined with respect to the longitudinal axis of the supporting rod are arranged at right angles to each other so that the scrapers supported on the slide members have their cutting surfaces fanned out at right angles to each other to define a circular cutting knife.

These and ancillary objects and structural features of merit are attained by this invention, a preferred embodiment of which is set forth in the following description, illustrated in the accompanying drawing, wherein:

Figure 1 is a vertical sectional view of a conventicnal well tubing, illustrating this invention being lowered therein;

Figure 2 is a similar View of the well tubing, depicting this invention in an upwardly moving position;

Figure 3 is a transverse sectional view taken on line 3-3 of Figure 2; and

Figure 4 is a view in perspective of the scraper or cutter instrument.

Referring now to the drawing, the numeral I!) designates a well tubing or casing of any conventional cross-sectional diameter. This invention, generally designated by the character reference I2, is adapted to be lowered and raised in the bore of the casing or tubing and is adapted to completely remove paraffin or other substances adhering to the inner surface of the casing.

The scraping device, 52, includes an elongated supporting or connecting rod 54, which is formed with an externally threaded upper end it. The end it is inserted in an internally threaded socket is formed in a coupling collar 29. The collar 2!) is provided at its opposing end with an externally threaded, axially reduced extension 22, the latter being adapted to be secured to conventional sucker rods.

An enlarged end 24 is formed on the lower end of the rod and is adapted to be lowered into the casing. A plurality of blocks or slide members 26 are arranged in end-to-end relationship between the collar Zil'and the enlarged end 24. Any number ofslide members may be provided and the length or other dimension thereof may be as desired or needed.

The slide members are formed with longitudinally disposed angular bores 21, the slide members being bored off-center with respect to the longitudinal axis thereof. Thus, when the slide members are strung in a series on the supporting rod, each of the slide members is out of longitudinal alignment with the adjacent slide member. The slide members are formed with a noncircular outer surface and each is provided with an upwardly and inwardly inclined side wall 28, the side wall 23 being inclined with respect to the longitudinal axis of the supporting rod Hi. Each of the slide members is positioned and locked on the supporting rod, so that the inclined face 28 thereof is disposed at right angles to the inclined side wall or face on adjacent members.

A sleeve 30 is slidably and non-rotatably disposed on the non-circular outer surface of the slide members, the sleeve being formed with a side wall 32, which is complementary to the inclined side wall 28 on each of the slide members. A semi-circular integral cutter 3 projects laterally from the lower edge of the outerisurface of the wall 32 of the sleeve and the upper edge 36 thereof is sharpened. A reinforcing, vertically disposed web 33 is disposed integrally between the upper face of the cutter 34 and the outer surface of the wall 32. If desired, the connecting or rigidifying web 38 may have its angular portion ie sharpened for scraping contact with the inner surface of the casing.

Each of the slide members 26 is provided with a slidably and non-rotatably disposed sleeve 39, from which integrally projects the cutter 34. The slide members 26 are disposed in an end-to-end relationship on the connecting or supporting rod M, so that the inclined side walls 28 thereof are disposed at right angles to each other. Thus, the cutters 3d are carried by the slide members in a manner to define a circular, continuous cutter, as seen in Figure 3.

When the cutting device 12 is lowered in the casing, through sucker rods supporting the 0011- meeting or supporting rod [6, the sleeves 30 will be moved upwardly on the slide members and the side walls 32 of the sleeves will be positioned at the. upper, innermost portion of the inclined side walls 28. Thus, the cutting edges 36 of the cutters 34" will be held out of contact with the innersurface of the casing.

However, when the device is moved upwardly the casing, the sleeves will slide downwardly on the slide members and the cutters will be held infrictional engagement on the inner surface of the casing, with the cutting edges 36 thereof. in scraping contact with the inner surface of the casing.

It must be appreciated that the upstroke of the device removes the paraiiin or similar substance from the inner surface of the casing forthe free flow of oil from the well, while the downstroke of the device will not remove any parafiin or similar substance, and thus will avoid scraping the paramn into the well.

However, since other purposes can be established for the instant scraping device, and since other embodiments may be practiced, limitation is sought only in accordance with the terms of the appended claims.

Having described the invention, what is claimed as new is:

l. A scraping device comprising, a supporting rod, a plurality of adjacentv slide members disposed on said rod and arranged in end-to-end engagement, each of said slide members being formed with an upwardly and inwardly inclined side wall'with respect to the longitudinal axis of the supporting rod, said side wall of each member being arranged at a right angle to the side wall of the adjacent member, and scrapers slidably and ncn-rotatably disposed on said slide members, each of said scrapers including an internal wall engaging the side wall of each of said slide members.

2. A well scraping device comprising a supporting rod, a plurality of non-circular slide members disposed on said rod and arranged in end-to-end relationship out of longitudinal alignment, each of said slide members being formed with an inwardly and upwardly inclined side wall with respect to the longitudinal axis of the rod, sleeves slidably and non-rotatably disposed on said slide members andcutting means laterally projecting from the portion of the sleeves disposed on the inclined side walls.

3. A well scraping device comprising a supporting rod, a plurality of non-circular slide members disposed on said rod and arranged in end-to-end relationship out of longitudinal alignment, each of said slide members being formed with an upwardlyand inwardly inclined side wall, said side walls being, arranged at right angles to each other, sleeves slidably and non-rotatably disposed on said slide members and formed with a side wall complementary to the inclined side walls and laterally projecting cutting means integrally formed on the saidside walls of the sleeves.

4. A well scraping device comprising a supporting rod, a plurality of non-circular slide members disposed on said rod and arranged in end-to-end relationship out of longitudinal alignment, each of said slide members being formed with an upwardly and inwardly inclined side wall, said side walls being arranged atright angles to each other, sleeves slidably and non-rotatably disposed on said slide members and formed with a side wall complementary. to the inclinedside walls and semicircular reinforced cutters integrally formed on the saidside wallsof the sleeves and projecting laterally therefrom.v

EMANUEL H. CHRISTOPHER.

REFERENCES CITED The following references. are of record in the file, of this patent:

UNITED STATES PATENTS Number Name Date 1,810,260 Swinford June 16, 1931 1,875,413 Braly Sept. 6, 1932 2,130,267 Cowen Sept. 13, 1938 2,397,679 Minyard Apr. 2, 1946 2,402,345 Ratigan 1 June 18, 1946 

